mortar for concrete having polyurethane foam and method of thereof

ABSTRACT

Disclosed are a mortar for concrete mainly consisting of urethane foam and a method for manufacturing the same, in which urethane foam and Styrofoam used as insulating materials for household electronic appliances and a pre-cast panel are not discarded, but recycled such that the urethane foam and the Styrofoam are mixed with concrete in the construction of flooring of apartments or an ondol of houses. Low weight structure, superior sound-absorption effect and heat insulation effect can be obtained, and cracks are prevented from being generated in the constructed part. Construction work is simplified, and economical efficiency is enhanced. Collected waste urethane foam and waste Styrofoam are pulverized into a size of 1 to 10 mm using a pulverizer. The pulverized urethane foam and Styrofoam are mixed to each other to form urethane foam. Admixture is added to the urethane foam, and then cement and water are mixed with the urethane foam in a predetermined ratio to form a lightweight insulating urethane foam concrete mortar using a mixer and a truck mixture. The lightweight insulating urethane foam concrete mortar is manufactured and is transported from a mixing area to a construction part such that materials of the concrete is prevented from being separated from each other. The concrete is poured using squeezing equipment and hydraulic transfer equipment and then cured for a predetermined curing time to prevent sudden change in the temperature.

TECHNICAL FIELD

The present invention relates to a mortar for concrete mainly consistingof urethane foam and waste synthetic resin and a method formanufacturing the same. More particularly, the present invention relatesto a mortar for concrete mainly consisting of urethane foam and a methodfor manufacturing the same, in which urethane foam and Styrofoam used asinsulating materials for household electronic appliances and panels forconstruction are not discarded, but recycled in such a manner that theurethane foam and the Styrofoam are mixed with concrete while inconstruction of ondol-flooring of apartments or houses. Therefore, a lowweight structure, superior sound-insulation effect and heat insulationeffect can be obtained, and cracks are prevented from being generated inthe constructed part. In addition, construction work is simplified andeconomical efficiency is enhanced.

BACKGROUND ART

Production amount of polyurethane foam, which is fabricated by using rawmaterials imported at expensive cost, is assumed as a volume of about450 to 500 thousand tons per year when taking the usage of the importedraw materials in to consideration. The polyurethane foam is used forvarious purposes in various fields. For instance, the polyurethane foamis used as insulating materials for household electronic appliancesincluding refrigerators or construction panels. However, the treatmentof the used polyurethane foam is not easy and reclamation orincineration is mainly used for treating the used polyurethane foam.

In general, since the polyurethane foam is a thermosetting resin, thepolyurethane foam is not melted by heat and the recycling ofpolyurethane foam is not easily achievable. In addition, even after thepolyurethane foam is incinerated, nitrogen and aromatic ring containedin the polyurethane molecules may remain. Also, in the case of thepolyurethane foam used as the insulating material, Freon (CFC) servingas a foaming agent remains in the polyurethane foam after incineration.The nitrogen contained in the urethane generates nitrogen dioxide,thereby causing environmental contamination. In addition, the nitrogengenerates fluorine, causing difficulty in treating the polyurethanethrough incineration. Further, since the polyurethane foam represents alow density, reclamation of the polyurethane foam is not easy, and sincethe polyurethane foam is hard-resoluble material, reclamation of thepolyurethane foam is rarely allowable.

Accordingly, there is a need for developing a technology capable ofeffectively recycling the waste polyurethane foam.

In this regard, applicant of the present invention has filed a methodfor manufacturing urethane foam concrete by mixing cement, sand andwater with squeezed urethane foam as represented in Korean PatentRegistration No. 391558. However, the use of sand is necessary in thetechnique described above, so the amount of sand used for constructionhas been increased, thereby causing a shortage of natural sand.Accordingly, the urethane foam concrete representing the above effectwithout using sand is needed.

DISCLOSURE OF INVENTION Technical Problem

The present invention has been made to solve the above problem occurringin the prior art, and an object of the present invention is to provide amortar for concrete mainly consisting of urethane foam and wastesynthetic resin that are not discarded after use, but recycled asconstruction materials when a flooring of apartments or houses isconstructed. Therefore, the constructed part has a low weight, superiorsound-insulation effect and heat insulation effect, cracks are preventedfrom being generated, construction work is simplified, and economicalefficiency is enhanced.

Technical Solution

The foregoing and/or other aspects of the present invention are achievedby providing a mortar for concrete mainly consisting of urethane foamand a method for manufacturing the same, the method comprising the stepsof forming urethane foam by collecting, pulverizing and mixing wasteurethane foam and waste Styrofoam (S1);

adding admixture to the urethane foam obtained (S2); and

mixing cement with the materials obtained through the above steps (S3).

The waste urethane foam and the waste Styrofoam are preferablypulverized into a size of 2 to 10 mm, and the pulverized Styrofoam andthe pulverized waste Styrofoam are preferably mixed in a weight ratio of5-7:1-3.

In addition, the admixture prevents materials of the concrete from beingseparated from each other and serves as a plasticizer. The admixturepreferably includes water-soluble cellulose ether based gray powder as amain composition.

In addition, in steps 2 and 3, the mortar preferably includes 60-80volume percent of lightweight urethane foam, 1-4 volume percent ofadmixture and 16-40 volume percent of cement. If urethane foam contentis less than 60 volume percent, the amount of cement is relativelyincreased, so economical efficiency is lowered. Meanwhile, if theurethane foam content is more than 80 volume percent, the strength ofthe concrete is too low to represent concrete properties. Accordingly,the above range of the urethane foam content is preferable. In addition,the admixture prevents the materials from being separated from eachother and serves as the plasticizer in the range described above. If thecement content is less than 16 volume percent, the compressive strengthof the concrete is remarkably lowered. If the cement content is morethan 40 volume percent, the amount of lightweight urethane foam isrelatively decreased, so that the concrete does not provide desiredeffects as alternative concrete.

The lightweight urethane foam mixed with the admixture and the cement ismixed with water in use by a conventional scheme to form urethane foamconcrete.

In addition, the present invention provides a mortar for concrete mainlyconsisting of urethane foam, in which the urethane foam includes 60 to80 volume percent of lightweight urethane foam obtained by mixing wasteurethane foam and waste Styrofoam, which are pulverized into a size of 2to 8 mm, in a weight ratio of 5-7:1-5, 1 to 4 volume percent ofadmixture, which prevents materials from being separated and serves as aplasticizer, and 19 to 40 volume percent of cement.

As described above, the present invention provides a method ofmanufacturing an insulating concrete material for construction byrecycling waste urethane foam, which is produced from waste householdelectronic appliances and construction panels and usually incinerated,and urethane foam concrete manufactured by the same.

ADVANTAGEOUS EFFECTS

As described above, the lightweight insulating urethane foam concreteusing a mortar according to the present invention can be used as alightweight insulating concrete in construction and civil engineeringfields by recycling waste urethane foam, which is included in a wasterefrigerator and a waste construction panel, as an insulating concretematerial for construction. Thus, the economical efficiency is enhancedin terms of recycling of resources.

In other words, according to the lightweight insulating urethane foamconcrete using a mortar of the present invention, specificallypulverized high quality urethane, which serves as insulating materials,is mixed with waste Styrofoam in a predetermined ratio to improve thesound absorbing effect, to prevent cracks from being generated, andenhance the heat insulation property and strength of the concrete. Inaddition, PPS admixture developed by applicant of the present inventionis added to the concrete to prevent materials of the concrete from beingseparated from each other and to improve plasticization property.Accordingly, material scattering, foam scattering in a surface ofconstructed building, damage to surrounding structures, such as a wallplaster board, a frame of doors and a chassis, during the operation of acompact sized cart type mixer, and homogeneous combination of mixture,which are caused by the current construction scheme of concrete foam,can be minimized. In addition, the lightweight insulating urethane foamconcrete represents superior effect without using sand having a problemin terms of supply, so economical efficiency is enhanced.

Accordingly, the mortar according to the present invention can beapplied to construction work, as material for the flooring of theapartment and house ondol, roof insulating concrete, the bottom of aparking lot, and the bottom of the basement. In addition, the mortar isapplied to structures in the civil engineering field for the tunnelgrouting, the backfilling for preventing subsidence, the winter-sowingprevention, the heat insulation and the corrosion prevention for exposedpipes and the vibration and impact absorption.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a preferred embodiment of the present invention will bedescribed in detail with reference to the accompanying drawings.

Recently, concrete foam, expandable concrete, expandable concrete foam,fiber mix expandable concrete, EVA (Ethylene-Vinyl Acetate) expandableconcrete foam, BST (Bituminous Surface Treatment) expandable concretefoam, and urethane shell expandable concrete are used for insulatingflooring in the construction of apartments or houses. Among them, theexpandable concrete has been widely used for convenience sake inconstruction. However, the expandable concrete has a problem in that itgenerates cracks in the insulating layer.

In order to solve the above problem, various additives have been addedto the expandable concrete, but the cracks are not effectively removedwith the additives.

Currently, even though the concrete foam is preferably used than theexpandable concrete, the concrete foam is not readily acceptable in theconstruction site since the insulating product businesses areincompetent for managing the construction site and the concrete foamproduct.

The present invention provides a mortar capable of manufacturinglightweight concrete used in flooring/wall insulating bricks that ispractically perfect in terms of commercial value and workability.

To this end, according to the present invention, waste urethane foamproduced from waste household electronic appliances, in particular,waste refrigerators or construction panels, is recycled to be used asconstruction materials. In addition, if the waste urethane foam is usedas the construction materials, the development of the insulatingconcrete capable of providing various advantages including lightweight,superior sound absorption, superior heat insulation and workability hasbeen expected. Accordingly, the present invention has been made tomanufacture a lightweight insulating urethane foam concrete by recyclingthe waste urethane foam such that the urethane foam concrete is used forthe flooring, the dry panels, and the bricks in the apartment houses. Inparticular, the present invention provides a method and a mortar formanufacturing urethane foam concrete, which does not contain sand havinga problem in terms of supply and demand and causing supply problem inthe construction site.

Exemplary Embodiment

According to the present invention, firstly, waste urethane foamgenerated from waste household electronic appliances or panels forconstruction is collected and pulverized into a size of about 1 to 10mm. Similarly, waste polystyrene (Styrofoam) is collected and pulverizedinto a size of about 1 to 10 mm. The pulverized urethane foam andStyrofoam are mixed with each other in a weight ratio of 7:3 to form alightweight urethane foam.

The lightweight urethane foam, admixture and cement are mixed with eachother in a ratio shown in Table 1 below, and then mixed with water in aproper ratio.

TABLE 1 (Unit: %: volume ratio) WASTE URETHANE FOAM:WASTE URETHANESTYROFOAM FOAM ADMIXTURE CEMENT 1 1 1 51 1 48 2 7 3 60 4 36 3 6 4 60 337 4 8 2 65 4 31 5 5 4 70 3 27 6 4 2 78 3 19 7 6 1 85 4 11

The admixture is usually used for exerting an influence oncharacteristics of the concrete, such as workability, bleeding, curingtime, compressive strength, change in length, neutralization, freezingand thawing process and thermal reliability against erosion by chemicalsubstances. In addition, the admixture is used for restraining hydraulicheat. The admixture according to the present invention includes graypowder, which mainly consists of water-soluble cellulose ether. Thecement is selected from products, which satisfy KSL 5201 and is suitablefor KSF 2526 having an age less than two months after the cement hasbeen manufactured. In addition, in the case of the mixing water, themixing water harmless to the concrete is selected in use.

Physical properties of the concrete using the mortar manufacturedthrough the above process are measured according to regulationsincluding KSL 5105, KSL 5207, KSL 5104, KSF 2451, KSL 9016, KSF 2451,KSF 2424, KSF 2810, etc.

The physical properties of the concrete according to the presentinvention are shown in Table 2 in comparison with those of the relatedart.

The materials of the concrete are mixed through a concrete mixer on theground of the construction site, and the mixed lightweight insulatingurethane foam concrete is transported from the mixing area to a pouringarea using a specifically developed pump such that the materials can beprevented from being separated from each other. In use of the concrete,if the conveyed materials of the concrete are applied to a constructionpart by a squeeze pump, the materials are evenly spread by usingspecific equipment and then the periphery of the concrete is flattenedby a rod. In the process of conveying or pouring the lightweightinsulating urethane foam concrete, if the materials are excessivelyseparated from each other, the concrete is subject to a remixing processsuch that the concrete can be uniformly mixed. In addition, aliensubstances are prevented from being introduced into the concrete, and anarea of the concrete, on which the alien substances are possiblyabsorbed, is wetted with water. When the concrete work is performedthrough at least two stages, concrete of a latter stage is poured beforeconcrete of a former stage is hardened such that the concrete of theformer stage is integrated with the concrete of the latter stage.

After the concrete has been poured, the concrete must be cured toprevent sudden change in the temperature. In addition, the concrete mustbe cured to prevent vibration, impact and excessive load from beingapplied to the concrete.

The curing period is at least 3 days in the summer season under thetemperature of 30° C. and at least 4 to 5 days in the winter season overthe temperature of 1° C. The curing process according to the presentinvention is performed similarly to the curing process of conventionalconcrete.

Result and Review

Table 2 represents the measurement result of curing characteristics forthe urethane foam concrete manufactured according to the embodiment ofthe present invention.

TABLE 2 PATENT CONCRETE NORMAL NO. FOAM USING CONCRETE TYPES CONCRETE391558 CONCRETE MORTAR Lightweight-air dried 2.3-2.4 0.4-1.8 0.4-1.20.4-2.0 gravity(t/m³) Mechanical properties-  50-400  5-250  5-45 11-200 compressive strength(kgf/cm²) Heat insulating property-thermal1.3-1.4 0.08-1   0.12-0.2  0.08-1.2  conductivity(kcal/m²h° C.) Moistureproof property- 10-18  5-10 40-60 4-9 absorptivity (%) Sound proofproperty- 0.01-0.04 0.09-0.19 0.2-0.8 0.07-0.15 acoustic absorptivity(%) Drying shrinkage-28 days- 4-6  0 4-8  0 shrinkageDurability-freezing/thawing 70-80 90 50 87 resistance (%) Fire proofproperty-compressive 10-20 50 50 58 strength(600° C., 2 h)(%) Vibrationproof property-energy 78 45 46

As shown in Table 2, the urethane foam concrete using the mortaraccording to the present invention has a specific gravity of 0.4 to 2.0whereas normal cement concrete has a specific gravity of 2.3 to 2.4. Inthis manner, the load of the concretes is reduced into less than a halfor a third of the load of the normal concrete, so that the constructioncost is reduced. In addition, the strength of the concrete is freelychanged within a range of 11 to 200 kgf/cm2 depending on the combinationof concrete. The concrete according to the present invention has athermal conductivity of 0.08 to 1.2 kcal/m2h° C. corresponding to a halfto a third of that of normal concrete (1.4 kcal/m2h° C.), so that theheat insulating effect is improved. In addition, the concrete accordingto the present invention has a superior adhesive property with respectto the mortar and forms a uniform mixture, thereby preventing cracks anddelaminating. Such an effect is almost identical to that obtained by theKorean Patent Registration No. 391558, which has been filed by applicantand the effect can be realized without adding sand.

In addition, since the urethane foam concrete using the mortar accordingto the present invention has an excessively superior moisture proofproperty as compared with other types of concrete, dew condensation,molds and germs do not exert an influence on the concrete. The concreteaccording to present invention has the most superior sound absorbingproperty as compared with other types of lightweight insulatingconcrete. In addition, shrinkage does not exist and cracks caused byexpansion/contraction are prevented from occurring in the concrete.Since the concrete can be hardened within a short hardening time of 3 to4 days, the construction period can be shortened and the subsequentprocesses can be readily performed. In addition, since the concreteaccording to the present invention has superior freezing/thawingresistance to other types of concrete, dew condensation andwinter-sowing are prevented. Since the concrete according to the presentinvention has superior impact energy absorptivity, vibration proofproperty is enhanced through absorption of vibration energy.

Although few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A method for manufacturing a mortar for concrete, the methodcomprising the step of: pulverizing waste urethane foam and wasteStyrofoam into a size of 1 to 10 mm, respectively; forming urethane foamby mixing the waste urethane foam with the waste Styrofoam in a weightratio of 5-7:1-3 and adding gray powder, which mainly consists ofwater-soluble cellulose ether and serves as an admixture, to theurethane foam, wherein the mortar includes 60-80 volume percent of theurethane foam, 1-4 volume percent of the admixture and 19-40 volumepercent of the cement.
 2. A mortar for concrete, the mortar comprising:60 to 80 percent of urethane foam, which is obtained by pulverizingwaste urethane foam and waste Styrofoam into a size of 1 to 10 mm andthen mixing the waste urethane foam with the waste Styrofoam in a weightratio of 5-7:1-3; 1 to 4 percent of gray powder, which mainly consistsof water-soluble cellulose ether and serves as an admixture; and 19 to40 percent of cement.